(FROM BIOL. BULL.) THE NON-INVASIVE TWO-DIMENSIONAL VIBRATING PROBE ASSEMBLY WAS USED TO INVESTIGATE THE CURRENTS ASSOCIATED WITH WOUND HEALING FOLLOWING AMPUTATION OF ANTERIOR SEGMENTS IN SABELLIDS. PORTIONS CONSISTING OF 15-20 ABDOMINAL SEGMENTS WERE ISOLATED FROM EACH WORM. MEASUREMENTS WERE MADE AT THE ANTERIOR WOUND SITE. THE GOAL WAS TO DETERMINE THE PATTERN OF NET IONIC FLUX DURING WOUND CLOSURE AND TO INVESTIGATE THE RELATIVE CONTRIBUTIONS OF DIFFERENT TISSUES DURING TRANSECTION. BECAUSE OF THE COMPLEXITY OF THE WOUND SURFACE, VOLTAGE GRADIENTS WERE MEASURED IN BOTH HORIZONTAL AND VERTICAL PLANES. THE RESULTING CURRENT PATTERN IS ALSO COMPLEX. THE RESULTS ARE CONSISTENT WITH THE HYPOTHESIS THAT STRONG POSITIVE CURRENTS LEAVE MOST OR ALL OF THE SEVERED TISSUES, RESULTING IN A NET OUTWARDLY DIRECTED FLUX FROM THE WOUND SITE AND THAT CURRENTS RETURN THROUGH THE ADJACENT EPIDERMIS AND, AT TIMES, THROUGH THE GUT LUMEN.